STILLWATER, Okla. -- A clear path beckoned to the Oklahoma State end zone.

Baylor quarterback Bryce Petty broke free and appeared ready to score the game's first touchdown Saturday night. It would have been the kind of start that the Bears' prolific point-a-minute offense had produced so many times this season.

But Baylor's luck was different Saturday night. Maybe it was accountable to a brutally cold night with wind chill factor well below freezing. Or maybe it was the record-breaking crowd of 60,218 at Boone Pickens Stadium. Whatever reason, Petty stumbled untouched at the OSU 1 to start a nightmare unraveling of the Bears' dream season.

"It wasn't something out of the ordinary, but we were shocked," Baylor coach Art Briles said about Petty's stumble. "It's something you come to expect to work opposite of what happened. That's a little disturbing."

It really got unsettling three plays later. Redshirt tailback Shock Linwood was stripped of the ball just short of the OSU end zone. The Cowboys then marched 99 yards on a game-changing drive that helped set the tone in a convincing 49-17 victory that boosted the Cowboys into control of the Big 12.

"It happens, you get too ahead of yourself at times," Petty said. "It was just a funky deal."

The Cowboys produced a stellar defensive effort that shackled the Bears in their lowest scoring effort of the season. OSU limited the Bears to two cosmetic touchdowns in the fourth quarter, long after they had established control of the game.

The fall came with a suddenness that shouldn't have been unexpected considering Baylor's previous struggles at Boone Pickens Stadium.

Baylor had a No. 4 ranking in the most recent BCS standings, the nation's most productive offense and a school-record 13-game winning streak.

But the Bears couldn't trump history as they saw their hopes for a national championship and likely a BCS berth evaporate on the chilly night. The loss extended Baylor's 11-game losing streak in Stillwater -- a losing streak that stretches since their last triumph there on Oct. 7, 1939.

"This is very difficult," senior linebacker Ahmad Dixon said. "Despite the score, the only number that's in my head is 1939, and 2013 didn't change 1939. This hurts."

The Bears (9-1, 6-1) will need some help to win their first Big 12 title. They will have to beat TCU and Texas in their final two games and hope that Oklahoma can upset OSU in their season finale.

"Our chances of still winning the Big 12 aren't over, but we wanted something bigger than that," Dixon said. "We wanted something that's never been done before and that was to go to a national championship. That dream came down. I promise the next one won't crash down on us."

OSU quarterback Clint Chelf, who was benched in the first half of the Cowboys' first game earlier this season, had a masterful game as he led the Cowboys to their seventh straight victory. It was also their first triumph over a top-5 ranked team since beating No. 3 Oklahoma in 2002.

OSU coach Mike Gundy cooked up an exotic game plan that featured gadget plays and heavy reliance early on a double-tight end formation that instead turned out to be productive through the air.

The Cowboys defense did the rest, often matching Baylor's substitution patterns just before the ball was snapped. They added to their conference-leading turnover margin with three fumble recoveries, two of which were turned into touchdowns.

But the biggest reason was their physical man defense against the Baylor receivers who produced only two gains of more than 30 yards.

"We moved around a lot and put hands on them and made them make plays," OSU safety Daytawion Lowe said. "We have good defensive backs and played physical with them. We just challenged the receivers and made them beat us."